Sink & tub safety

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If current is flowing through the victim, there's no reason to believe the return path is the neutral. How would the person come in between the hot and neutral?

I'm in the "don't require it" camp. If a shock is going to hurt someone, the GFCI will trip. It's more effective to control the source of the shock (install a GFCI) than to assure one return path and expect it to contribute to the tripping of the GFCI.

Besides, with the number of plastic drains, it would not be a very effective code, at least in my neck of the woods. ;)
 
georgestolz said:
Besides, with the number of plastic drains, it would not be a very effective code, at least in my neck of the woods. ;)
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I agree.

I was trying to figure out how we would bond the little metal ring on the drain inside the tub.:eek:
 
My thinking is, if an appliance is dropped in the water, current can only flow from hot to nuetral. This will not trip a GFCI. If a person sticks thier hand in the water, current will still flow from hot to nuetral. The GFCI will only trip if current is flowing to ground through another source, i.e. a shared nuetral or a ground fault. Please explain to me how the GFCI will trip if current is flowing between hot and nuetral.

I must be missing something here. Please explain it to me. If the hair dryer is dropped into the water and the H.O. puts his hand in the water, current is still flowing from hot to nuetral. How will the GFCI trip? There is no ground fault.
 
sparky_magoo said:
My thinking is, if an appliance is dropped in the water, current can only flow from hot to nuetral. This will not trip a GFCI. If a person sticks thier hand in the water, current will still flow from hot to nuetral. The GFCI will only trip if current is flowing to ground through another source, i.e. a shared nuetral or a ground fault. Please explain to me how the GFCI will trip if current is flowing between hot and nuetral.

I must be missing something here. Please explain it to me. If the hair dryer is dropped into the water and the H.O. puts his hand in the water, current is still flowing from hot to nuetral. How will the GFCI trip? There is no ground fault.
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I see your point, so the real question is will the current flow outside of the short path between the hot and the neutral within the hair dryer? If not than where is the shock potential?
 
sparky_magoo said:
I must be missing something here. Please explain it to me. If the hair dryer is dropped into the water and the H.O. puts his hand in the water, current is still flowing from hot to nuetral. How will the GFCI trip? There is no ground fault.
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I think the main principle behind the GFCI is that a very small current across the heart will kill the victim.

If current leaves the black, travels through the pinky finger, through the hand, out the thumb, to the white, that shouldn't be a fatal shock. (Not that it wouldn't hurt, begin to cook the hand, or that I recommend doing it to impress girls.) It would also be hard to do. Both these conductors are guarded. The ungrounded conductor is actively seeking a path back to the source, so it will try it's best to make it happen.

The more likely circumstance is black through unpure water to hand, through the heart to the foot, out the foot to ground, through ground to transformer. In this circumstance, the victim could certainly be killed and the GFCI will trip.
 
I'd like to clear this up for my own information. Assuming that I'm standing on a insulated floor and not touching anything else. Will I get shocked if I stick both hands into water and grab a energized hair dryer that is in the water? I don't plan to try this, but it would be good to know. Would my body somehow become parallel with the current (if any) flowing thru the water?
I just don't see how it can happen.
steve
 
hillbilly said:
I'd like to clear this up for my own information. Assuming that I'm standing on a insulated floor and not touching anything else. Will I get shocked if I stick both hands into water and grab a energized hair dryer that is in the water? I don't plan to try this, but it would be good to know. Would my body somehow become parallel with the current (if any) flowing thru the water?
I just don't see how it can happen.
steve
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Yes current would flow from one hand to the other through the water.
 
jwelectric said:
Yes current would flow from one hand to the other through the water.
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I disagree unless you place something in the tub that the current is flowing to.


Example one

Drop a 'hot' in the tub water, now place one hand in the tub (your not grounded) no shock.

Place a second hand in the water still no shock as there is no difference of potential from one hand to the other.


Example 2

Drop a hot in the tub at one end and a ground in at the other end.

Place one hand in (your not grounded) no shock

Now place the other hand in the water and you may get a shock as the water around one hand will be at a different potential than the water around the other hand.

To me this is the same as 'step potential' around a grounding electrode only this time we can call it swimmers (or fools) potential. :)
 
That I can understand. It takes potential for current to flow. Another example....If I strip the insulation from a conductor a distance of say 6' (could be more or less), and touch the wire at one end of the exposed area (all of this while being insulated from ground), no current will flow, no shock.
If, while touching this one exposed area, I use the other hand to touch the other exposed end (placing my body in parallel with the wire), current will flow thru my body. The mount of current that will flow will depend on the potential (in the wire) between the two exposed areas that I touch. This potential will be the result of the voltage and the resistance of the conductor between the two points. Thus if the resistance goes down (better conductor), less current flow thru my body. If the resistance goes up (poor conductor), more current flow thru my body. If the resistance in the wire is gradually increased, at some point my body would carry most of the current. This would happen when my body's resistance became lower than the wire conductor. If while touching the wire, I slide my hands closer together, the current flow will diminish and ultimately stop when my hands touch each other. This is the same scenario that requires parallel conductors to be made of the same material, the same length and terminated in identical manner to try to match the resistance of the conductors as closely as possible. If they're not, one conductor will carry more current than the other.

I don't plan to do this experiment, nor do I recommend anyone else trying this.
Just some food for thought.
steve
 
hillbilly said:
That I can understand. It takes potential for current to flow. Another example....If I strip the insulation from a conductor a distance of say 6' (could be more or less), and touch the wire at one end of the exposed area (all of this while being insulated from ground), no current will flow, no shock.
If, while touching this one exposed area, I use the other hand to touch the other exposed end (placing my body in parallel with the wire), current will flow thru my body. The mount of current that will flow will depend on the potential (in the wire) between the two exposed areas that I touch. This potential will be the result of the voltage and the resistance of the conductor between the two points. Thus if the resistance goes down (better conductor), less current flow thru my body. If the resistance goes up (poor conductor), more current flow thru my body. If the resistance in the wire is gradually increased, at some point my body would carry most of the current. This would happen when my body's resistance became lower than the wire conductor. If while touching the wire, I slide my hands closer together, the current flow will diminish and ultimately stop when my hands touch each other. This is the same scenario that requires parallel conductors to be made of the same material, the same length and terminated in identical manner to try to match the resistance of the conductors as closely as possible. If they're not, one conductor will carry more current than the other.

I don't plan to do this experiment, nor do I recommend anyone else trying this.
Just some food for thought.
steve
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This would be a good science fair project, Although I would recommend using a couple of multi-meters instead of a human guinea pig.:D
 
This is starting to sound quite a bit like 'bare hand bonding on' as used for maintenance on high tension lines. Perhaps we should require equipotential bonding straps attached to the users of the bathroom :)

-Jon
 
winnie said:
This is starting to sound quite a bit like 'bare hand bonding on' as used for maintenance on high tension lines. Perhaps we should require equipotential bonding straps attached to the users of the bathroom :)

-Jon
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:D

Other than that how our we doing?

Am I close or just talking trash? :p
 
winnie said:
Perhaps we should require equipotential bonding straps attached to the users of the bathroom :)

-Jon
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There is a strong temptation on my part to make a comment about a 3/8" ground rod clamp being the appropriate attachment method, but I think I will pass.
 
Joe Todesco video

Joe Todesco video

One of my co-workers started a thread on a corporate bulletin board about circuit breakers. Somehow the topic of GFCIs, hair dryers bathtubs came up and I was wondering if anyone here remembered a link Joe posted where he put running blow dryers in sinks full of water and the blow dryer didn't trip the GFCI.

You can make some computer geeks very happy if you provide the links ;)
 
all this talk about water, hair driers,and sticking your hands in it makes me think of that neat little trick uncle fester did with the light bulb.:grin:
 
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